1. Technical Field
The present invention is directed to a robust and compact haptic feedback system, more specifically, a haptic system that economically and reliably constrains movement of the interface surface to a single axis of motion to minimize potential for damage to a haptic feedback driver and more specifically, to a compliant mounting apparatus or member for haptic feedback systems that is capable of constraining motion of a haptic interface or interface surface in a single axis of movement.
2. Discussion
To improve and enhance ability to interface with various electronic devices, many manufacturers have added haptic feedback systems to various devices. In general, haptic feedback systems interface with a user via the sense of touch by applying forces, vibrations, and/or motions to the user. While haptic feedback devices can be used in a variety of devices, one particular area where haptic feedback is useful is touch screen interfaces or compact mechanical button interfaces, where the ability to visually interact is limited or reduced, such as for operators of vehicles, or smaller devices where size is a concern, such as inputs for cell phones and other portable electronic device. More specifically, haptic feedback systems are very helpful in providing the user with feedback without visual confirmation by the user, especially where the input member is too small to easily see, such as a touch screen keypad on a mobile phone. This haptic feedback is very useful in situations where the ability of the user to visually confirm actions may be constrained such as an operator of a vehicle attempting to provide input to or change settings on the vehicle, such as to climate control systems, GPS systems, and entertainment systems. More specifically, in motor vehicles, to minimize distraction during operation of the vehicle, haptic feedback systems provide the user with a touch feedback allowing the user to confirm that the desired input was properly entered and received by the vehicle while allowing the user to stay visually focused where needed during operation of the vehicle.
One type of haptic effect can be generated from a haptic effect driver that is a linear actuator. One problem with haptic effect drivers in particular haptic systems that have panel style input surfaces actuated in a single degree of freedom is that the haptic feedback driver providing the haptic motion to the haptic or interface surface may be damaged when forces are applied in directions other than along the axis of the haptic feedback motion. As interface surfaces have increased in size, such as large touch screen displays, and particularly, those haptic feedback systems integrated into moving vehicles, the potential for off-axis forces being applied to the haptic feedback driver has increased. There are also many areas in a vehicle that may be subject to impact or contact due to shifting loads, operator movements or passenger movements in getting in and out of the vehicle. In summary, the concern is that any applied off-axis force may damage the haptic feedback driver and prevent it from operating properly.
To address off-axis forces, some manufacturers have attempted to constrain motion of the interface surface through slides or other devices. These devices tend to be heavy, increase the friction and thereby the force required to move the interface surface as well as, in some instances, is susceptible to reduced operational performance due to dust or other contaminants over time. Any increase in required force to move the haptic surface or interface surface requires a more robust and larger haptic feedback driver which increases the cost of the system. In addition, most attempts to constrain motion of the interface surface results in additional material costs and additional assembly costs. Furthermore, it is important that the haptic feedback surface is not affected by environmental contaminants such as dirt, dust or even sticky solutions such as soda or juice being spilled on it as commonly can happen with many devices. The effect of environmental contaminants in these haptic systems is that the longevity of the haptic feedback driver or the ability of the haptic feedback driver to provide sufficient haptic motion to interface surface may be reduced or eliminated, primarily due to failure of the devices used to constrain motion.
In addition, the assembly and attachment of a haptic surface to a base is complex and the system allowing haptic motion is expensive and bulky. They also can be difficult to assemble.
Therefore, a need exists for a simple, easy to assembly, lightweight, low-cost, robust, and reliable haptic feedback system capable of constraining movement of an interface surface to movement that is substantially aligned to the axis of movement of the haptic feedback driver.